The Analysis Of Sub-Synchronous Oscillation Of The Wind-Thermal Bundling System Composed Doubly Fed Induction Generators

Nowadays,with the continuous development of power technology and responding to the call of the country for "Energy Conservation and Emission Reduction",the development of clean energy has made rapid progress.Among them,the wind power plant has been widely used in our country as a relative mature and efficiently clean power generation method.It is of great significance to study the influencing factors and suppression of sub-synchronous oscillation in doubly-fed wind farms.At present,the research on the influencing factors of sub-synchronous oscillation of wind-fired bale power generation system has significant practical significance.In this paper,wind-fired bale power generation transmission system as an example,the study of wind and fire bundling system sub-synchronous oscillation characteristics and prediction detection method.The main contents of this paper are as follows:Based on the existing research,the model of wind-power bale power generation transmission system was established based on the derivation of wind turbine aerodynamics model,fan drivetrain system model,wind turbine pitch angle control system model and doubly-fed induction fan controller model.Analysis the control strategy of inner ring and outer ring of the DFIG-BASED wind farms and analysis the small signal stability factors.The phenomenon of sub-synchronous resonance caused by small signal interference of DFIG in windward fire bales is theoretically analyzed.And the simulation model of wind-fire bale power generation system is built on the platform of PSCAD/EMTDC,only the main components model of doubly-fed induction fan is simulated.When the DIFG wind turbine is disturbed by small signal,the influence of the parameters of its sensing controller on sub-synchronous harmonics Impact.Verify the above theoretical analysis according to the simulation waveform.Based on the oscillating model of synchronous turbine shaft system,the effect of sub-synchronous oscillation induced by doubly-fed induction wind farm on the entire wind-fired bale system and steam turbine power generation system is theoretically analyzed.Taking the first IEEE standard as an example,a model of wind-fire bale power generation system was built on the PSCAD/EMTDC platform and tested.Small signal disturbance was applied to doubly-fed induction fan to observe the turbine output waveform in the wind-fire bale system.The controller parameters of the doubly-fed induction generator were adjusted and the output waveform of the turbine was observed.Then the small-signal disturbance of doubly-fed induction fan And turbine system,and analyze its influencing factors.Small signal disturbance was applied to doubly-fed induction fan to observe the turbine output waveform in the wind-fire bale system.The controller parameters of the doubly-fed induction generator were adjusted and the output waveform of the turbine was observed.Then the small-signal disturbance of doubly-fed induction fan and turbine system,and analyze its influencing factors.This paper presents a method of sub-synchronous oscillation prediction for wind-fired bale power generation system,that is,an improved method of determining the unit operating coefficient,in the process of specific calculation and analysis,consider the effect of multi-harmonic wave filtering device on wind-fire bundled transmission line.Under the conditions of HVDC transmission,if the HVDC rectifier station is close to the wind-fire bundled power plant,this method is used to predict whether there is any danger of sub-synchronous oscillation,Its technical specifications can provide theoretical support and information for whether in-depth sub-synchronous oscillation studies are needed or whether sub-synchronous harmonics should be suppressed using tandem or parallel TACTS devices.The research results above show that the small-signal interference sub-synchronous oscillation phenomenon of wind-fired bale power generation transmission system is theoretically analyzed and verified by simulation.It has important reference value for the stable operation of wind power system and will be the research on the detection method and suppression strategy of sub-synchronous oscillation Lay the theoretical foundation and decision support.